Drying apparatus.



W. H. BRADLEY. DRYING APPARATUS. APPLIGATION FILED sBPT.14, 1908.

962, 1 1 8 Patented June 21,1910.

3 SHEETS-SHEET 1.

W. H. BRADLEY. DRYING APPARATUS. APPLICATION FILED SEPT. 14, 1908.

' Patented June 21, 1910.

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Iman/072' WMM, ffm@ W.VH. BRADLEY. DRYING APPARATUS. APPLICATION FILED sEPT.14, 1908.

Patented June 21, 1910.

3 SHEETS-SHEET 3.

UNITE@ STATES ATEN- FFMJE.

WILLIAM I-I. BRADLEY, OF` CHICAGO, ILLINOIS.

DRYING APPARATUS.

Specification of Letters Patent. Patgntedl Jun@ 21, jlgl,

Application filed September 14, 1968.

Serial No. 452,965.

To all whom it may concern:

Be it known that I, WiLLrAM H. BRADLEY, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a new and useful .Improvement in Drying Apparatus, of which the following is a specification.

My invention relates particularly to a process and apparatus for use in drying wet peat; and my primary object is to provide a process capable of producing an improved peat product and simple and efficient apparatus which can be economically operated inthe practice of said process.

My invention is particularly adapted to the purpose, among other purposes, of removing the water of absorption from wetpeat mass after the peat mass has been preparatorily treated, if necessary, to remove foreign substances and to remove water of suspension, where the preparatory treatment involves the use of an excess amount of water. For instance, the wet peat mass may be taken from a centrifugal machine, in which the water of suspension is separated from the peat, and the wet peat mass may be advantageously and economically treated in the apparatus herein shown for the purpose of removing water of absorption, that is, drying the peat to any desired degree.

The invention is illustrated in it-s preferred embodiment in the accompanying drawings, in which- Figure 1 represents a broken elevational view of drying apparatus constructed in accordance with my invention; Fig. 2, an enlarged broken sectional view, showing details of construction of the boilers, or chambers, in which the moisture is separated from the peat, together with the means for transferring the material through the chambers and from chamber to chamber; Fig. 3, a broken sectional view, on an enlarged scale, of the mechanism employed for feeding the wet material to the drying apparatus; and Fig. 4, a plan view of a portion of the mechanism shown in Fig. 3.

It may be stated here that I employ a series of cylinders, or boilers, through which the material to be dried is moved by means of conveyers, maintaining successively reduced pressuresin said cylinders, transfer the material from cylinder to cylinder, out of atmospheric contact, and employ the steam from one cylinder to heat another,

.for feeding the wet material to the drying apparatus.

The apparatus A preferably comprises a cylinder, or'boiler, 1, located in a furnace 2; a series of cylinders, or boilers, 3, 4, 5 and 6, through which the material is fed in succession after leaving the boiler 1; steam-jackets 7 for the boilers 3 to 6 inclusive; connecting and transferring devices 8 serving to transfer the material from cylinder to cylinder; screw-conveyers 9 extending longitudinally of the cylindrical boilers; a superheating coil 10 having one end connected with the boiler 1 and the other end connected with the first steam-jacket 7; a superheating coil 11 having one end connected with the dome of the first device 8 and the other end connected with the first steam-jacket 7; series of exhaust pipes 12, 13, 14 and 15 connected with the boilers 3 to 6 inclusive; a condenser 15a connected with said pipes; and gearmechanism 16 serving to actuate the screwconveyers mentioned and the rotary members of the transferring devices 8.

The mechanism A1, which serves to feed the wet material into the drying apparatus, comprises a pipe 17 which connects at one end with vthe front end of the cylinder 1 and terminates at the other end in branches forming a Y 18, as shown in Fig. 4; cylinders 19 connected with the branches of the eov Y 18; plungers 20 working in said cylinshown) which serve to operate the plungers 20. Each plunger 20 is equipped with a circuit-closer 27 adapted to close the circuit 25 and set the motor 24 in operation when the plunger 2O is retracted. Each plunger 20 is equipped with a semi-cylindrical valve 28, constituting a forward projection, which 25 v rear end 31 at the point of connection with serves to close the outlet to the hopper when the plunger moves forward s0 that the ma-` -exerted by the plunger. Upon the return stroke of the plunger, the valve closes automatically under the pressure behind it. The plungers work in alternation, thereby inl suring a certain uniformity` of feed.

From the foregoing explanation it will be understood that the wet material is forcedv through the pipe 17 in to the cylinder 1 under suitable ressure, the passage through lthe pipe 17 eing sealed by the l'material against back-pressure from steam generated in the cylinder 1. The cylinder 1 extends through the furnace 2 and has a reduced .the first transferring device 8. The superheating coil 10 connects with the cylinder 1 in advance of the contracted portion 31 and is provided at some distance in front of its connection with the steam-jacket 7 with a pressure-valve 32. 7The steam coil 11 connects with the dome of the first transferring device .8. Eachtransferring device 8 comprises a chamber, or dome, 33 in communication with the cylinder in advance of it; a casing 34 whose open upper end is surmounted by the chamber 33 and whose openA lower end connects with an ,upturned pipe 35 at the front end of the next succeeding cylinder, p contained in the casing 34, by'means nf which the material is transferred, without appreciably affect-ing the difference in the pressures maintained inthe successive b oilers. The casing 34 has curved sides adapted to permit rotation of the member 36; and

y the member 36 has wings or vanes crossing spectively, with pressure-valves,

each other at its axis, so that as the member rotates the pressure will not be permitted to,

pass from lone cylinder to the other. The pipes 12, 13,- 14y and 15 are lprovided,`re or reducing valves, 37, 38, 39 and 40. The frontend of te gips 12' is connected, by a pipe 41, with t e 8 and with the 'steam-jacket 7 of the cylinder 4. Similarly, the pipe 13 is connected,

-by a pipe 42,'with the'dome of the third transferring device8 and with the steamjacket 7 of the cylinder 5. The pipe 14 is connected, by a pipe 43, lwtith the dome of thenext transferring device and with the jacket of the cylinder 6. The pipe 15 is connected with "the domeof the lasttransferring or boiler; and a rotary member 36 v ome of the second transferring device last transferring. device l8 is adaptedvto dei liver the material into the atmosphere, the material being allowed to drop upon any suitable conveyer or into any suitable place of storage (not shown).

device 8, and it may be stated here that the The condenser 15 is equipped with an eX- n haust-pump 44, as shown in Fig. 1.

The gear-mechanism 16 may comprise any suitable construction and arrangement. As shown, it ycomprises a shaft 45 serving to operate belts, or chains, 46, connected with the rotary members 36 of the transferring devices 8, and serving also to operate belts, or chains, 47, connected with the screw-conveyers 9.

The operation will be understood from the foregoing detailed descriptioin- The wet peat, or other wet solid, usually infa plastic state, is fed into the hoppers 22 in any suitable mannerand thence into the cylinders 19. The plungers 2O operate alternately to force the material through the pipe 17 into the boiler 1. By means of the furnace, the boiler 1 is heated and the material therein raised to a comparatively high tem erature,

say a temperature of 300', more or ess, and steam generated in the cylinder-1 is superheated to any desired degree and passed into the rst steam-jacket 7. The material, issuing from the cylinder, or boiler, 1; is transferred by the first transferring device 8 to the cylinder or boiler 3, through which it is transferred, by the screw-conveyer operatmg therein. successively lower pressures vare maintained in thecylinders or boilers of the multiple-effect drying apparatus, and the latent heat of th'e steam from one cylinder may thus be-employed to boil the material in the next cylinder. By preference, the

drying-operation is finished at about atmospheric pressure, or a little above atmospheric pressure, and the compacted and dried peat thus issues into the atmosphere in a state enabling it to be freely handled without dan er of crumbling. As the material is passed through the eonveyers, it is subjected to endless tumbling while the drying proceeds, and forms in pellets, or balls, so

that it issues in convenlent form for use.

It will'be understood from the foregoing description that the material is dried out of atmospheric contact, and as stated, the dryving operation is preferably completed at or near atmospheric pressure. It is to be noted, also, that during the drying -process the central portions of the peat-masses, balls, or pellets, are at higher temperature than the 'exterior portions, so that there results a constant expulsion of the moisture from the center outward. The drying continues under such conditions as-to obviate the premature formation f an exterior crust, so.that cracking of the pellets is` avoided; and, moreover, the drying is effected under pressure, which is lowered by gradations, so that a uniform compacting upon or condensing about the center of each pellet is effected, the result being an exceedingly hard, uniformly compacted product practically impervious to water and free from danger ofcrumbling.

The foregoing detailed description has been given for clearness of understanding only, and no undue limitation should be understood therefrom.

I/Vhat I regard as new, and desire to secure by Letters Patent, is-

l. In apparatus for the purpose set forth, the combination of a series of boilers, means formaintaining dierent pressures in said boilers, and means for transferring solid material from one boiler to another.

2. In apparatus of the character set forth,

the combination of a furnace, a boiler contained therein, a series of boilers adapted to receive the material in succession after it passes from the first boiler, means for transferring solid material from one boiler to the next boiler throughout the series, said means adapted to prevent the fiow of pressure from boiler to boiler, means for heating each boiler succeeding the first boiler, said means receiving, as a heating fluid, the steam generated in the preceding boiler, and means -for maintaining different pressures in the several boilers.

3. In apparatus of the character set forth, the combination of a series of boilers, means for mechanically moving material through said boilers and transferring the same, out of atmospheric contact, from boiler to boiler, means for feeding a wet,` solid under-pressure into the first boiler, means for employing the steam generated in oneboiler to heat the succeeding boiler throughout the series, and means for maintaining successively reduced pressures in said boilers.

4. In apparatus of the character set forth, the combination of a series of boilers, screwconveyers operating to feed the material therethrough, connecting devices joining the boilers in series and equipped with rotary transferring devices adapted to prevent the flow of pressure from boiler to boiler, means for maintaining different pressures in said boilers, and means for heating the several boilers.

5. In apparatus of the character set forth, the combination of a boiler', means for heating said boiler, a succeeding boiler equipped with a steam-jacket, means for transferring material from the first boiler to the second boiler, a steam-jacket for the second boiler, and a superheater receiving its steam supply from the first boiler and discharging it into the jacket of the second boiler.

6. In apparatus of the character set forth, the combination of a furnace, a boiler heated thereby, means for feeding a wet solid under pressure into said boiler, a superheater in said furnace receiving its steam supply from said boiler, a series of boilers equipped with steam-jackets, transferring devices connecting said boilers in series, a connection between said superheater and the first steamjacket, and means for conducting steam from the second boiler to the jacket of the third boiler, and so on throughout the series.

7. In apparatus of the character set forth, the combination of a furnace, a boiler heated thereby, means for feeding a wet solid under pressure into said boiler, a superheater in said furnace receiving its steam supply from said boiler, a series of boilers equipped with steam-jackets, transferring devices connecting said boilers in series, a connection between said superheater and the first steamjacket, means for conducting steam from the second boiler to the jacket of the third boiler, and so on throughout the series, and exhaustdevices connected with the several boilers and equipped with means for maintaining different pressures therein.

8. In apparatus of the character set forth, the combination of a series of boilers, transferring devices connecting the boilers in series and adapted to convey wet solids from boiler to boiler, means for maintaining successively reduced pressures in said boilers, a heating device for each boiler receiving, as a heating fluid, steam from a preceding boiler, and means for forcing a wet solid. into the first boiler, comprising a cylinder and plunger.

9. In means of the character set forth, the combination of a plurality of boilers arranged in series, transferring devices connecting the boilers in series and adapted to transfer solid materials from boiler' to boiler, screw-conveyers in said boilers, -means for maintaining different pressures in said boilers, means for heating said boilers, and means for feeding a wet solid into the first boiler, comprising a plunger and a conduit equipped with an automatically opening and closing valve.

10. In apparatus of the character set forth, the combination of a series of boilers equipped with jackets, transferring devices connecting said boilers in series, conduits haust device, conduits connecting said eX- Ahaust device with said boilers, pressure devices connected With said conduits serving to maintain different pressures in said boil` ers, andmeans for conducting steam from each boiler and applying the same to heat the next succeeding boiler.

12. In the treatment of peat, the process of removing Water of absorption which consists in mechanically moving the Wet peatv mass and subjecting it, While in motion, to successive heat-effects out of atmospheric tact, under successively reduced pressures.

13. In the treatment of peat, the process of removing Water of absorption which consists in moving the Wet peat mass through a chamber and subjecting it therein to a given heat and pressure, transferring the material mechanically, out of atmospheric contact, to another chamber in which a lower pressure is maintained, and subjecting the material to a heat-effect in the second-named chamber.v

14. In the treatment of peat, the process of removing Water of absorption, which con,

sists in heating the Wet mass of peat to a high temperature in a chamber, collecting and superheatingthe steam taken from the mass, passing the mass into a second chamber, and employing the superheated steam to heat the second receptacle.

15. In the treatment of peat, the process vof removing Water of absorption, which consists in passing the Wet peat mass through a series of chambers, applying heat to the mass at one chamber, maintaining. successively reduced pressures in said chambers,

lit to heat the second chamber,

and employing the latent-heat of steam from one Ichamberl to boil the mass in the next chamber.

16. In the treatment of peat, the process of removing Water of absorption, which consists in passing the wet peat through a series of chambers, applying heat to the mass at one chamber, collecting and superheaotingv steam from the first chamber and employing maintainmg l successively reduced pressures in the several chambers, and employing the steam from the second chamber to heat the third chamber, and so on through the series.

17. In the treatment of peat, the proce of removing ,Water` of absorption, which consists in heating the Wet peat mass and subj jecting it to successive heat-effects at successively reduced pressures and out of atmospheric cont-act, and employing the latent heat of steam taken from one chamber to boil the material in the next chamber.`

18. In the treatment of peat, the process of removing Water of absorption, which consists in heating the Wet peat mass and subjecting it to successive heat-effects under successively reduced pressures.

19. In the treatment of peat, the process of removing Water of absorption which consists in heating the Wet peat mass out of atmospheric contact to a high temperature and under a pressure" above atmospheric pressure, and subjecting the heated mass to successive heat-effects out of atmospheric contact and undersuccessively reduced preS-,

SUIBS.

20. In the treatment of peat, the process of removing-Water of absorption Which consists in heating the Wet peat mass out of atmospheric contact to a high temperature and under a pressure above atmospheric pressure, subjecting the heated mass'to successive heat-effects out ofv atmospheric contact and under successively reduced pressures, and ending the treatment under a pressure near atmospheric pressure.

21. In the treatment of peat, the process of removing Water of absorption, which con--L 

